Chapter 4 CELL PHYSIOLOGY

OBJECTIVES I will be able to compare the processes of diffusion, dialysis, facilitated diffusion, osmosis, and filtration. Discuss the active cell transport mechanisms responsible for movement of some materials through cell membranes. Compare and contrast passive and active cell transport processes. Describe the role of enzymes in cell metabolism. We will Outline the process of cellular respiration and discuss its importance. Discuss, compare, and contrast the four distinct phases of mitosis and meiosis. Discuss and give examples of how cells adapt to changing conditions and what kinds of changes may be harmful to the body.

MOVEMENT OF SUBSTANCES THROUGH CELL MEMBRANES (P. 91) Passive transport processes (Table 4-1) Diffusion (Figs. 4-1, 4-2, 4-3) Diffusion Dialysis (Fig. 4-4) Separation of small from larger molecules Osmosis (Figs. 4-5, 4-6) Osmosis Diffusion of water across a selectively permeable membrane ( osmotic pressure)

MOVEMENT OF SUBSTANCES THROUGH CELL MEMBRANES (P. 91) Passive transport processes (Table 4-1) Facilitated diffusion (Fig. 4-7) Facilitated diffusion Carrier mediated Filtration Water passage by force of hydrostatic pressure Separate large from small Capillaries

MOVEMENT OF SUBSTANCES THROUGH CELL MEMBRANES (P. 91) Active transport processes (Table 4-1) Substances move against a gradient; using pumps pumps Endocytosis (Fig. 4-9) Phagocytosis Pinocytosis Exocytosis (Figs. 3-2, 3-5)

CELL METABOLISM/ENZYMES (P. 98) Enzymes reduce activation energy Regulate cell metabolism Chemical structure of enzymes (Fig. 4-10)enzymes Proteins Active site

CELL METABOLISM/ENZYMES (P. 98) General functions of enzymes Most enzymes are action-specific (Fig. 4-10) Chemical and physical agents activate or inactivate by changing shape (Figs. 4-11, 4-12) Allosteric effectors (give me some examples) End-product inhibition occurs Most enzymes catalyze reversible reactions

COMP-BOOK WRITING ASSIGNMENT Write 5-6 sentences Explain the similarities and differences between active and passive transport. Give examples of each and where in our body the process occurs.

CELL METABOLISM/ENZYMES (P. 98) General functions of enzymes Many enzymes are synthesized as inactive pro-enzymes (Fig. 4-11)

CATABOLISM (P.102) Overview of cellular respiration (Fig. 2-29) Glucose is broken down to yield stored energy Glycolysis (what is the fate of Pyruvic acid?) (Figs. 4-13, 4-14) Citric acid cyc le (Figs. 4-14, 27-6) Electron transport system (Figs. 4-14, 27-7)

ANABOLISM (P.104) Building pathways Deoxyribonucleic acid (DNA) (Figs. 4-15, 4-16) Double helix; transfers information; directs protein synthesis Genes = segment of DNA; codes for synthesizing one polypeptide (amino acid compound)

Process of using tRNA to convert the mRNA strand into stings of amino acids proteins Converting DNA to mRNA to prepare for protein synthesis ANABOLISM (P.104) Transcription (Fig. 4-14; Table 4-2) Translation (Figs. 3-3, 4-18, 3-5; Table 4-2)

GROWTH AND REPRODUCTION OF CELLS (FIG ) Cell growth (p. 109) Production of cytoplasm (Table 4-2) Amount of cytoplasm doubles preparing for separation DNA replication (Fig. 4-20; Table 4-3) Chromosomes double Genetic material same in all cells (mitosis) Genetic material in haploid number (meiosis)

GROWTH AND REPRODUCTION OF CELLS Cell reproduction (p. 111) Cytokinesis (Fig. 4-22) Mitosis (Table 4-4; Fig 4-22) Prophase (Figs. 4-21; 4-22, B) Metaphase (Fig. 4-22, C) Anaphase (Fig. 4-22, D) Telophase (Fig. 4-22, E) Meiosis (Fig. 4-23) (Covered in more detail in Chapters 31–33) Meiosis I Meiosis II

GROUP ASSIGNMENT You will act out the phase of mitosis you are given. Shhhh it’s a secret and your classmates have to guess You will be in groups of 5-6 and everyone must participate.

MITOSIS Interphase 46 chromosomes

MITOSIS Prophase Chromosomes doubled (92)

MITOSIS Metaphase Nucleus dissolves Microtubules attach Chromosomes align at the middle

MITOSIS Anaphase Separated chromosomes pulled apart

MITOSIS Telophase Microtubules disappear Cell division occurs

MITOSIS Cytokinesis Two daughter cells are formed 46 chromosomes each

CYCLE OF LIFE: CELLS (TABLE 4-5) Different cells have different life cycles Aging creates cell numbers and function Muscles atrophy Loss of skin elasticity Bone density Cardio and respiratory

THE BIG PICTURE: CELLS PHYSIOLOGY AND THE WHOLE BODY (P. 116) Most process occur at the same time throughout the body Genetic code dictates normal cell functions

MECHANISMS OF DISEASE (P. 116) Cellular Disease Disorders involving cell transport (Fig. 4-24) Cystic fibrosis Chloride ion pump in cell membrane are missing Salty and thick mucous secretions Duchenne muscular dystrophy Leaky cell membranes; false muscle growth Disorders involving cell membrane receptors Type 2 diabetes Insulin receptors less sensitive; cells starved for glucose located outside the cell but can not get in

MECHANISMS OF DISEASE (P. 116) Cellular Disease Disorders involving cell reproduction Cancer Disorders involving DNA and protein synthesis Sickle-cell anemia Abnormal hemoglobin production Infections Bacterial and viral damage to cells

CELL METABOLISM/ENZYMES (P. 98) Classification and naming of enzymes (-ase) Oxidation-reduction enzymes (give me 2 examples) Hydrolyzing enzymes (Found where?) Phosphorylating enzymes (add or remove what?) Enzymes that add or remove carbon dioxide (?) Enzymes that rearrange atoms within a molecule (?) Hydrases (what do they do with water?)